diff --git a/Cargo.toml b/Cargo.toml
index 4ee335c..bb9ccb0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -43,3 +43,7 @@ micro-bench = []         # for benchmark, do not enable it in normal use
 name = "micro"
 harness = false
 required-features = ["micro-bench"]
+
+[profile.bench]
+opt-level = 3
+lto = true